[PATCH][v2] ipa/100308 - properly update the callgraph when pruning EH in IPA CP

[Richard Biener]

This makes sure to fall into the delete_unreachable_blocks_update_callgraph
handling to remove blocks becoming unreachable when removing EH edges
by tracking blocks to need EH cleanup and doing that after releasing
dominance info.

This fixes an ICE seen with gfortran.dg/gomp/pr88933.f90 when enhancing
DSE.

2021-04-28  Richard Biener  <rguent...@suse.de>

        PR ipa/100308
        * ipa-prop.c (ipcp_modif_dom_walker::before_dom_children):
        Track blocks to cleanup EH in new m_need_eh_cleanup.
        (ipcp_modif_dom_walker::cleanup_eh): New.
        (ipcp_transform_function): Release dominator info before
        doing EH cleanup.
---
 gcc/ipa-prop.c | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/gcc/ipa-prop.c b/gcc/ipa-prop.c
index 010c43f33e8..02c483b10dd 100644
--- a/gcc/ipa-prop.c
+++ b/gcc/ipa-prop.c
@@ -5514,17 +5514,20 @@ public:
   ipcp_modif_dom_walker (struct ipa_func_body_info *fbi,
                         vec<ipa_param_descriptor, va_gc> *descs,
                         struct ipa_agg_replacement_value *av,
-                        bool *sc, bool *cc)
+                        bool *sc)
     : dom_walker (CDI_DOMINATORS), m_fbi (fbi), m_descriptors (descs),
-      m_aggval (av), m_something_changed (sc), m_cfg_changed (cc) {}
+      m_aggval (av), m_something_changed (sc) {}
 
   virtual edge before_dom_children (basic_block);
+  bool cleanup_eh ()
+    { return gimple_purge_all_dead_eh_edges (m_need_eh_cleanup); }
 
 private:
   struct ipa_func_body_info *m_fbi;
   vec<ipa_param_descriptor, va_gc> *m_descriptors;
   struct ipa_agg_replacement_value *m_aggval;
-  bool *m_something_changed, *m_cfg_changed;
+  bool *m_something_changed;
+  auto_bitmap m_need_eh_cleanup;
 };
 
 edge
@@ -5616,9 +5619,8 @@ ipcp_modif_dom_walker::before_dom_children (basic_block 
bb)
        }
 
       *m_something_changed = true;
-      if (maybe_clean_eh_stmt (stmt)
-         && gimple_purge_dead_eh_edges (gimple_bb (stmt)))
-       *m_cfg_changed = true;
+      if (maybe_clean_eh_stmt (stmt))
+       bitmap_set_bit (m_need_eh_cleanup, bb->index);
     }
   return NULL;
 }
@@ -5876,7 +5878,7 @@ ipcp_transform_function (struct cgraph_node *node)
   struct ipa_func_body_info fbi;
   struct ipa_agg_replacement_value *aggval;
   int param_count;
-  bool cfg_changed = false, something_changed = false;
+  bool something_changed = false;
 
   gcc_checking_assert (cfun);
   gcc_checking_assert (current_function_decl);
@@ -5907,15 +5909,16 @@ ipcp_transform_function (struct cgraph_node *node)
   vec_safe_grow_cleared (descriptors, param_count, true);
   ipa_populate_param_decls (node, *descriptors);
   calculate_dominance_info (CDI_DOMINATORS);
-  ipcp_modif_dom_walker (&fbi, descriptors, aggval, &something_changed,
-                        &cfg_changed).walk (ENTRY_BLOCK_PTR_FOR_FN (cfun));
+  ipcp_modif_dom_walker walker (&fbi, descriptors, aggval, &something_changed);
+  walker.walk (ENTRY_BLOCK_PTR_FOR_FN (cfun));
+  free_dominance_info (CDI_DOMINATORS);
+  bool cfg_changed = walker.cleanup_eh ();
 
   int i;
   struct ipa_bb_info *bi;
   FOR_EACH_VEC_ELT (fbi.bb_infos, i, bi)
     free_ipa_bb_info (bi);
   fbi.bb_infos.release ();
-  free_dominance_info (CDI_DOMINATORS);
 
   ipcp_transformation *s = ipcp_transformation_sum->get (node);
   s->agg_values = NULL;
-- 
2.26.2